Chain reaction is a psionic power demonstrated by Sarah Kerrigan during the Second Great War. Using it, Kerrigan was able to allow her energy blasts to arch, hitting multiple targets.
Heart of the SwarmEdit
Kerrigan's attacks deal normal damage to primary target, then hits up to four adjacent enemy targets, dealing 10 damage to each secondary target.
In Legacy of the Void, Chain Reaction deals 25 damage to each secondary target.
In Co-op Missions, Sarah Kerrigan gains the chain reaction upgrade at level 9.